By comparison, about 36,000 people die of seasonal flu in the United States each year, and several hundred thousand are hospitalized.

Because people do not have immunity to the strain, H1N1 "poses a serious health threat to the nation," the report said.

Already in the United States, between April 15 and July 24, 2009, more than 43,000 people have fallen ill with swine flu and 302 have died, according to the U.S. Centers for Disease Control and Prevention (CDC).

The virus has swept the globe during the Southern Hemisphere's winter, killing nearly 1,500 people.

The World Health Organization estimates that H1N1 could infect 1 of every 3 people before the pandemic runs its course—about two billion people worldwide.